Problem is that with A/C, the compressor needs to be on the opposite side of the engine from the alternator. Prestige's serpentine system has the compressor tucked underneath the alternator and won't fit in the RCR chassis. I used a v-belt system with alternator, waterpump & crankshaft pulleys supplied by CVF Racing. They can supply you with a kit that has everything you need except a compressor mounting bracket. I used the one supplied by RCR. Some guys on the forum have made their own.
HTH, Rod